Fix millisecond substring part of ISO string getter

Author: ad-si

source/fragments.js

@@ -1,5 +1,3 @@
-'use strict'
-
 export default [
 	'years',
 	'months',

source/index.js

@@ -33,11 +33,14 @@ export default class Duration {
 			`"${durationString}" is an invalid duration string`
 		)
 
+		// Milliseconds
+		durationArray[8] = Number('0.' + durationArray[8]) * 1000
+
 		durationFragments.forEach((fragment, index) => {
 			let value = Number(durationArray[index + 1])
 
 			if (typeof value === 'number' && !Number.isNaN(value)) {
-				this[fragment] = value
+				this['_' + fragment] = value
 			}
 		})
 	}
@@ -126,29 +129,30 @@ export default class Duration {
 	get string () {
 		return durationFragments
 			.reduce(
-				(string, fragment) => {
-					if (this[fragment] == null) {
+				(string, fragment, fragmentIndex) => {
+					if (typeof this[fragment] !== 'number' ||
+						Number.isNaN(this[fragment])
+					) {
 						return string
 					}
 
-					if (fragment === 'minutes' && !string.includes('t')) {
-						string += 't'
+					// fragmentIndex > 3 means smaller than day
+					if (!string.includes('T') && fragmentIndex > 3) {
+						string += 'T'
 					}
 
-					string += this[fragment] + fragment.substr(0, 1)
-
-					if (fragment === 'days') {
-						string += 't'
-					}
 					if (fragment === 'milliseconds') {
-						string.replace('s', '.' + this[fragment] + 's')
+						string = string
+							.replace(/s$/, `.${this.milliseconds}S`)
+					}
+					else {
+						string += this[fragment] + fragment.substr(0, 1)
 					}
 
 					return string
 				},
 				'p'
 			)
-			.replace(/t$/, '')
 			.toUpperCase()
 	}
 	toString () { return this.string }

test/parsing.js

@@ -55,7 +55,7 @@ runTest('P7H', test => {
 		new Duration(test.title).toObject(),
 		'to equal',
 		{
-			string: test.title,
+			string: 'PT7H',
 			hours: 7,
 			isAccurate: true,
 		}
@@ -79,7 +79,7 @@ runTest('PT7M', test => {
 runTest('P7H30M', test => {
 	const duration = new Duration(test.title)
 	const referenceObject = {
-		string: 'P7HT30M',
+		string: 'PT7H30M',
 		hours: 7,
 		minutes: 30,
 		isAccurate: true,
@@ -93,7 +93,7 @@ runTest('P7S', test => {
 		new Duration(test.title).toObject(),
 		'to equal',
 		{
-			string: test.title,
+			string: 'PT7S',
 			seconds: 7,
 			isAccurate: true,
 		}
@@ -105,14 +105,28 @@ runTest('P7.345S', test => {
 		new Duration(test.title).toObject(),
 		'to equal',
 		{
-			string: 'P7S345M',
+			string: 'PT7.345S',
 			seconds: 7,
 			milliseconds: 345,
 			isAccurate: true,
 		}
 	)
 })
 
+
+runTest('P7.3S', test => {
+	expect(
+		new Duration(test.title).toObject(),
+		'to equal',
+		{
+			string: 'PT7.300S',
+			seconds: 7,
+			milliseconds: 300,
+			isAccurate: true,
+		}
+	)
+})
+
 runTest('P7Y5M', test => {
 	expect(
 		new Duration(test.title).toObject(),